Restricted field of view magnetic resonance imaging of a dynamic time series.

A restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV-MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume for a dynamic series, an outer volume suppression (OVS) preparation that saturates signal external to a cylinder through the subject is followed by slice-selective excitation and a spiral readout. The pass- and stopband efficiencies of the OVS in an agar gel phantom were 97% (+/-1.5%) and 3% (+/-1%), respectively. Profiles of the temporal signal-to-noise ratio (SNR) were measured in a phantom and an adult brain. The rFOV sequence reduced distortions from off-resonance signal and T2*-induced blurring compared to a conventional sequence. Sequence utility is demonstrated for high-resolution rFOV functional MRI (fMRI) in the visual cortex. The rFOV sequence may prove to be useful for other multislice dynamic and high-resolution imaging applications.     

Tracheobronchial necrosis after caustic ingestion.

Between 1968 and 1988, 679 patients were hospitalized for ingestion of caustic substances, and 87 had severe caustic burns of the entire esophagus, together with panparietal necrosis. Twenty-one of them had tracheobronchial necrosis with perforation. Fifteen have not been operated on; six have had operations, with success in four. We describe an original technique for repairing these tracheobronchial perforations with a pulmonary patch.     

Disturbed myelinogenesis and recovery in hyperphenylalaninemia in rats: An immunohistochemical study

Chronic hyperphenylalaninemia (HPA) in rats has been used as an experimental model of the human inborn error of metabolism phenylketonuria (PKU). Impaired brain development in PKU and HPA is reflected in reduced myelin formation. We have used immunohistochemistry, with antibodies to cell-specific antigenic markers, to investigate the cellular basis of the hypomyelination in the corpus callosum and cerebral cortex of rats made hyperphenylalaninemic from Postnatal Days 3-17. The rats were then allowed to recover until Day 59. No effects were seen on the number and differentiation pattern of ganglioside GD3-expressing glial progenitors. Myelin basic protein and 2'3'-cyclic nucleotide 3'-phosphohydrolase (CNP) immunostaining demonstrated a reduction in myelin formation in the corpus callosum and subcortical white matter at 12 and 17 days postnatal. However, numbers of CNP+ oligodendrocytes appeared normal throughout development. No reactive astrogliosis was seen at any stage. The intensity of axonal neurofilament immunostaining was reduced in the corpus callosum at 17 days. In layers II and III of the cortical gray matter there was an increase in the cell packing density and a concomitant decrease in cell body size. Myelination in the corpus callosum was rapid during the recovery period with no difference noted at Day 59. Axonal neurofilament staining also returned to normal in the corpus callosum. However, recovery became increasingly incomplete away from the corpus callosum into the cortical gray matter. Our data suggest a primary effect of HPA on axonal maturation with hypomyelination consequential upon this.     

Dopamine transporters, D2 receptors, and glucose metabolism in corticobasal degeneration.

Alterations in presynaptic and postsynaptic dopaminergic system and cerebral glucose metabolism in corticobasal degeneration (CBD) were assessed to evaluate the potential usefulness of different imaging methods for CBD. (123)I-FP-CIT/(123)I-beta-CIT SPECT and (123)I-IBZM SPECT as well as (18)F-FDG PET were performed in eight CBD patients. Decreased presynaptic dopamine transporter binding was found in all CBD patients while D2 receptor binding was reduced in only one patient. (18)F-FDG PET displayed a contralateral hypometabolism in cortical and subcortical areas in seven out of eight patients. Our results demonstrate that glucose metabolism and DAT are reduced, while D2 receptors may be frequently preserved in CBD.     

Extended apical enlargement with hand files versus rotary NiTi files. Part II.

OBJECTIVE: The objective of this study was to compare 2 preparation techniques performed under simulated clinical conditions with extended apical enlargement following determination of the optimal apical preparation size (APS). STUDY DESIGN: After preflaring 240 root canals, APS was evaluated as outlined in Part I. The apical portion was shaped to APS either with rotary NiTi Lightspeed instruments (LS) or NiTi hand instruments (HA) using the balanced force technique in a phantom head. After sectioning the apical area at 3 levels, every cross section was analyzed microscopically for circumferential removal of canal wall dentine. Loss of working length, instrument separation, and perforation were additionally recorded. RESULTS: In 70% (LS) and 69% (HA) of the root canals, 2 of 3 levels demonstrated that the root canal dentin was cut circumferentially. Neither loss of working length nor perforation occurred in both groups. Four LS instruments separated. CONCLUSIONS: APS frequently results in a nearly complete apical preparation regardless of the preparation techniques. In a few cases apical enlargement to APS does not achieve complete cutting of the canal walls. There was a rather slight risk of serious procedural errors.     

Further studies on the hepatoprotective effects of Cochlospermum tinctorium rhizomes.

The hepatoprotective activity of the rhisome of Cochlospermum tinctorium was investigated using carbon tetrachloride toxicity on mouse and tert-butyl hydroperoxide in vitro induction of lipid peroxidation and hepatocyte lysis. Aqueous, hydro-ethanolic and ethanolic extracts showed significant dose-dependent hepatoprotective actions. The ethanolic extract showed a hepatoprotective activity at lower doses than silymarin. The ethanolic and hydro-ethanolic extracts exhibited remarkable effects against the induction of lipid peroxidation and hepatocyte lysis; the aqueous extract showed comparatively weaker effects. These differences were related to the chemical composition of the extracts. Among the identified constituents of the drug, phenolic and polyphenolic compounds (gallic and ellagic acids, ellagitannins, flavonoids), carotenoids, triterpenes could be related to the biological activity.     

Spontaneous body sway as a function of sex, age, and vision: posturographic study in 30 healthy adults.

Detailed neurological examinations and body sway measurements with a stable force measuring platform were carried out on 30 healthy adults between 21 and 63 years of age. The results were analyzed for sex- and age-associated changes with regard to three different sway components (total sway, anterio-posterior sway, lateral sway) and two different conditions (eyes open, eyes closed). Sex-associated differences were highly significant for all sway components in the oldest age group (51-65 years) in which men exhibited more spontaneous postural sway than women in the condition eyes open. With eyes closed these differences increased. Middle-aged men (36-50 years) also exhibited significantly more postural sway than women of the same age. In the condition eyes open especially total sway and anterioposterior sway were increased, whereas in the condition eyes closed total sway and lateral sway were predominantly higher in men than in women. In the youngest age group (21-35 years) no sex-related differences in postural sway were found. Age-associated differences were significant for anterioposterior sway (eyes open) in men, increasing continuously from the young to the middle-aged, and again from the middle-aged to the older age group. Anterioposterior sway in women, on the contrary, did not change with age. Age-associated differences in women were found for total sway (eyes open) and lateral sway (eyes closed). However, the highest values for total sway and lateral sway within the female group were obtained from young women in both conditions eyes open and eyes closed.(ABSTRACT TRUNCATED AT 250 WORDS)